The default argument to HTMLTableElement.insertRow() should be -1, not 0, according to the specification:
Firefox 29 and IE11 both match the specification. Blink is about to change its behavior as well:
Created attachment 230996 [details]
Comment on attachment 230996 [details]
Clearing flags on attachment: 230996
Committed r168428: <http://trac.webkit.org/changeset/168428>
All reviewed patches have been landed. Closing bug.
*** Bug 138067 has been marked as a duplicate of this bug. ***